1. Field of the Invention:
This invention relates to improvements of the camera of the type having an automatic focus detecting device and electromagnetic release shutter, and, more particularly, to the provision of one actuator for coordination control of initiation and termination of a focusing operation by the aforesaid automatic focus detecting device and of initiation and termination of an exposure operation by the aforesaid electromagnetic release shutter.
2. Description of the Prior Art:
In the past, the cameras equipped with photo-electrically or echo-electrically operated object distance detecting devices controlling the operation of auto-focus mechanisms and with automatic exposure control apparatus using electrical actuating signals, or electrically operated shutters have been widely put into practical use.
It is also known to provide a camera equipped with an electromagnetic release mechanism rendering it possible for the electrical signal to actuate not only the above-described electric shutter but also other mechanisms within the camera.
Recently, therefore, attempts have been made to combine these functions in a single camera with an advantage that the complexity of mechanical structure and coordination control is reduced thanks to the use of electrical signals in controlling the entire operation of the camera. This leads to the possibility of improving the accuracy and reliability of control of the various portions of the camera. In the conventional camera of the type described above, it is, however, required that every portion of the camera be provided with a respective individual driver responsive to that electrical signal for producing a mechanical output signal. Since these drivers occupy a large space in the interior of the camera housing, a difficult problem arises that a further minimization of the bulk and size of the camera is no longer achieved. Further, since this driver generally takes the form of an electromagnet, or electric motor, because of its being of relatively high price, as the number of drivers in use is increased, the production cost of the camera is caused to increase. This has been one reason why such camera has a very high price.
On the other hand, however, with such situations in mind, much effort has been devoted to reduce the necessary number of the drivers, for example, electromagnets, as, for example, proposed in Japanese Patent Application No. Sho 53-63974 (Patent Application Laid Open No. Sho 54-155830). This Patent Application only discloses an improvement wherein the exposure control electromagnet is arranged so that the armature is made slidingly movable in two steps relative to the yoke with the first step initiating an exposure, and the second step terminating the exposure. Thus, the use of one driver or electromagnet suffices in controlling the sequence of the initiation and termination of an exposure-making operation of the electromagnetic release shutter. Therefore, all the above-mentioned drawbacks of the conventional camera have not been eliminated.